Septic pump frequency

I recently inspected a part time lake residence where the septic system was 9 years old. The owner stated they had never had the tank pumped and since they used the house infrequently, they didn’t think it needed to be pumped.
I told my buyer client I thought it would be a good idea to have the owner pump it and offered to go back and observe it when they did since the buyers were three hours away.
I was amazed at what we found:

  • 1200 gallon two compartment tank: 800 gallons main, 400 secondary.
  • main tank was roughly half full with secondary tank almost empty
  • main tank appeared to have almost no sludge and very little toilet paper present
  • The riser at the baffle showed no evidence of flow from the main tank to the secondary tank (see attached photo)

The tank pumper, who is very experienced and thought of highly in the community, said he sees this a lot with seasonal residences that don’t get a lot of use.
I asked him if the tank might be leaking but said it was not. The tank was doing its job by the sludge taking care of itself through normal bacterial action and the house vent system evaporating the liquid at a rate only slightly lower than the rate of flow into the system.
I found this interesting and wonder if any one else has run across this.

Gary, what is that a photograph of? I don’t make out 2 chambers, inlet or outlet or baffles. Something appears to be broken or split, but I can’t tell what I’m looking at.

Never thought of that, sounds very possible and credible coming from a tank pumper.

I had mine pumped after 8 years, the guy said I could have waited much longer.
I wanted to make sure it was working normally before something clogged my drain field.

Many people never have them pumped but even when it is working fine some clogs can grow at the inlet that could end up causing buildups in the main house pipe over time.

“This property is served by a private waste system that we do not have the expertise to inspect, and you should consider having it evaluated by a specialist. However, we do recommend the use of biodegradable tissues, soaps, detergents, and other cleaners, and that you avoid deposing of grease within the system. You should have its location identified because our experience shows that they are sometimes covered by decks, pools, driveways, etc., which would make service difficult and costly.”

Yes, I’ve seen a few like that over the years, Gary. It is kind of eerie when you first notice that the second tank is clean. I wondered the same thing about it leaking.

Kenton, you are looking down on top of the oulet baffle that enters the second chamber/tank. Notice how clean and unstained the concrete of the baffle is? The liquid can be seen in the first chamber above but not the second chamber below, in the picture as it is oriented.

Be careful about septic inspections. Does your state have licensing requirements for inspectors? As for the part-time resident, you may see all types of designs and what they may be holding. If the system has not been used, and then the owners come in and everyone takes showers, bathroom breaks, etc the system can be overloaded real quick and does not allow for the normal breakdown of waste. Also, I’m not saying the pumper you talked about, but some will only pump the main and go on their way or what they can get to. There are many factors involved, take a course if you have not already and find a Mentor, it would be well worth the time.

Your findings are not unusual given that you said:

Given enough time without use, solids break completely down and liquids evaporate. A septic system is magic. I’ve seen 10-year old, seasonal mountain home 3-stage tanks where the effluent has NEVER reached the dosing tank. In other words, the use is so infrequent that the field is still brand new.

Anyway, I agree with Steven about taking a course:

Thanks guys for your responses and input:
Thanks for your spot on read of the photo interpretation that Kenton asked about. (Jack Johnson the pumper form Manton said the tank was made right here in Cadillac, too bad they went out of business! Dox-Plank was also a great product!!!) Jack was also complaining about the Traverse City “repaired” wastewater plant and their requirement for the outlying areas to truck septage waste to their plant, it is going to double the cost of his services to consumers. Apparently the boundry line is on his road and even though he has his own approved treatment area, he has to truck his own tank waste to the TC plant but he can handle his neighbors tank across the street!.
Our State does not have license requirements on septic inspections yet but a few Counties are starting to have Point of Sale inspection requirements where you do need to be certified through the local Health Department.
Thanks for your input on the seasonal use impact on the septic tank, I knew it was a factor but am amazed on the extent.
I have taken the septic course and found it quite usefull. I also give out Bens book “Now that you’ve had a HOME inspection” and will follow-up with this client by reinforcing the brief section he has in his book by sending them some additional input on the future impacts if they change the usage to full-time.